Chemical weathering in a loess-mantled landscape, the Matanuska Valley, Alaska

Chemical weathering fluxes are generally enhanced by high physical erosion rates, yet glaciers, which have high physical erosion rates, have low silicate weathering fluxes due to low temperatures. Chemical weathering may be more significant where glacial erosion products are deposited than at the site of erosion; specifically, glacial loess deposits should increase weathering fluxes due to their fine grain size. In this study, chemical weathering fluxes were calculated using a mass-balance approach along a 35 km transect of loess-derived soils in the Matanuska Valley of South-Central Alaska.; In depositional landscapes, parent material can be nonhomogeneous due to varying composition over time and distance from sediment sources. A 17-meter thick loess deposit on a bluff of the Matanuska River was analyzed for parent material variability. The sediment in this deposit did not vary in mineralogical or elemental composition over its depth and is similar in composition to river sediments. (Abstract shortened by UMI.)...